Sorry to open this up again but I guess I don't understand the problem. A sanitary sewer wet well is typically a Class 1 division 1 or 2 area per NFPA 820 depending if it is ventilated or not. I was taught and I believe it to be NEC compliant to bring the pump cables (furnished with the submersible pump) up into a junction box in conduit, splice the pump conductors to THHN/THWN in the junction box on terminal strips or wire nuts and put the seal on the conduit with the THHN/THWN going to the starter/vfd or motor service disconnect. No seal is required between the pump and the J-box as the J-box does not have any arcing equipment in it.